Tanti Ardiyati | De La Salle University (original) (raw)

Papers by Tanti Ardiyati

E3S web of conferences, 2024

The working principle of the combined cycle in the combined cycle power plant (CCPP) is to utiliz... more The working principle of the combined cycle in the combined cycle power plant (CCPP) is to utilize a certain amount of waste heat in the gas turbine, which reaches temperatures of 1650°C, to generate steam in the steam turbine. Due to the high temperature of the exhaust gas in the gas turbine, a device is needed to recover this waste heat, known as a Heat Recovery Steam Generator (HRSG). Compared to conventional HRSG, a once-through heat recovery steam generator (OTHRSG) offers the advantages of faster design time (25% faster than conventional) and lower design costs because it does not require a drum which contributes to an increase in thermal efficiency. This study aims to model and simulate the CCPP system with an OTHRSG to achieve maximum thermal efficiency by using biogas from the degradation of organic waste as the input fuel for CCPP using Cycle Tempo software. The thermal efficiency of the CCPP system was achieved at 57% by applying turbine inlet temperature (TIT) of 1500°C and compression ratio of 46. These results proved that the CCPP system by using biogas as fuel could increase the thermal efficiency of a single cycle power plant.

XVII MEXICAN SYMPOSIUM ON MEDICAL PHYSICS

Nucleation and Atmospheric Aerosols, 2019

h i g h l i g h t s A 3D coupled thermo-hydrogeological numerical model of an ATES system is pres... more h i g h l i g h t s A 3D coupled thermo-hydrogeological numerical model of an ATES system is presented. Importance of a few parameters involved in the study is determined. Thermal energy discharge by the ATES system for two seasons is estimated. A strategy and a safe well spacing are proposed to avoid thermal interference. The proposed model is applied to simulate a real life ATES field study.

Atom Indonesia, Apr 16, 2019

In order to anticipate station blackout, the use of safety system based on passive features is hi... more In order to anticipate station blackout, the use of safety system based on passive features is highly considered in advanced nuclear power plant designs, especially after the Fukushima Dai-ichi nuclear power station accident. An example is the application of natural circulation in the emergency cooling system. To study the reliability of such an application, a research project on natural circulation was carried out. This paper describes the investigation results on the natural circulation phenomena obtained using a large rectangular experimental loop named FASSIP-01. The experiments were conducted at two different heat source powers. The experimental results are analysed using existing correlation and numerical model simulation. The RELAP5 system code is applied to model the natural circulation. FLUENT computational fluid dynamic code is used to visualize the flow distribution. The experimental results show the establishment of stable natural circulation in all heat power input with the mass flow rate of about 0.0012 kg/s. Calculation using the existing correlation shows that the experimental Reynold numbers are lower than predicted by the correlation. The computational fluid dynamics-based tool could show the three dimensional distribution of the temperature, while the model of RELAP5 predict well the dynamic of the singlephase natural circulation established in the experimental loop. It is concluded that the stable natural circulation have been established in the large rectangular loop and the model of the RELAP5 could simulate the observed natural circulation phenomenon reasonably well.

Spektra: jurnal fisika dan aplikasinya, Dec 30, 2022

Experiments on making a plastic scintillator with polystyrene as a base material mixed with fluor... more Experiments on making a plastic scintillator with polystyrene as a base material mixed with fluorescent compounds (primary and secondary dopants) have been performed. Primary dopants (PTP) used to produce emission at wavelengths of visible light and secondary dopants (POPOP) to shift the visible wavelengths to wavelengths that could be detected by Photomultiplier Tube (PMT)) were carried out. Experiments were performed on the melting points condition of these materials, which had previously been subjected to a thermo-mechanical analysis using a Thermogravimetric Analysis-Differential Scanning Calorimetry (TGA-DSC) machine, where the melting point was in the range of 200-240°C. Furthermore, the fabrication was carried out using the extrusion technique, where polystyrene pellets mixed with PTP (1.5% by weight) and POPOP (0.05% by weight) were fed into an extrusion machine which has four hot areas to obtain a thin plate plastic scintillator. The plates were then analyzed with a UV-Vis Spectrophotometer to determine the absorption spectrum and Fluorescence Spectrophotometer to determine the emission spectrum. From the results of the analysis, it was found that the samples that went through scintillation pellets and without the addition of antioxidants had absorption spectrum data of 330 nm and emission spectrum of 421 nm. These values are in

Atom Indonesia, Dec 12, 2019

To enhance the thermal safety in case of station blackout, a wickless-heat pipe is proposed as an... more To enhance the thermal safety in case of station blackout, a wickless-heat pipe is proposed as an alternative passive cooling system technology to remove decay heat generation in the nuclear spent fuel storage pool. The objectives of this research are to investigate the heat transfer phenomena in vertical straight wicklessheat pipe using Graphene nanofluid working fluid and to study the effect of Graphene nanofluid on the vertical straight wickless-heat pipe thermal performance. The investigation was conducted in 6 meters height and 0.1016 m inside diameter of vertical straight wickless-heat pipe. In this research, the Graphene nanofluid with 1 % of weight concentration was used as working fluid. The effect of working fluid filling ratio, evaporator heat load, and coolant volumetric flow rate on the water jacket were studied. The results showed that the heat transfer phenomena, which were indicated by an overshoot, zigzag, and stable state, were observed. Based on thermal resistance obtained, it was shown that the vertical straight wickless-heat pipe charged with the Graphene nanofluid has a lower thermal resistance compared to one with demineralized water. The thermal resistance of vertical straight wickless-heat pipe using Graphene nanofluid and demineralized water were 0.015 °C/W and 0.016 °C/W, respectively. While the best thermal performance was achieved at a filing ratio of 80 %, higher heat load, and higher coolant volumetric flow rate. It can be concluded that Graphene nanofluid could enhance the thermal performance of vertical straight wickless-heat pipe.

Spektra: Jurnal Fisika dan Aplikasinya

Experiments on making a plastic scintillator with polystyrene as a base material mixed with fluor... more Experiments on making a plastic scintillator with polystyrene as a base material mixed with fluorescent compounds (primary and secondary dopants) have been performed. Primary dopants (PTP) used to produce emission at wavelengths of visible light and secondary dopants (POPOP) to shift the visible wavelengths to wavelengths that could be detected by Photomultiplier Tube (PMT) ) were carried out. Experiments were performed on the melting points condition of these materials, which had previously been subjected to a thermo-mechanical analysis using a Thermogravimetric Analysis-Differential Scanning Calorimetry (TGA-DSC) machine, where the melting point was in the range of 200-240°C. Furthermore, the fabrication was carried out using the extrusion technique, where polystyrene pellets mixed with PTP (1.5% by weight) and POPOP (0.05% by weight) were fed into an extrusion machine which has four hot areas to obtain a thin plate plastic scintillator. The plates were then analyzed with a UV-Vis...

Coconut methyl ester (CME) or coconut oil biodiesel was chosen as the emulsifier for the diesel-e... more Coconut methyl ester (CME) or coconut oil biodiesel was chosen as the emulsifier for the diesel-ethanol blends. This study involved the stability testing and determination of physical and emission properties of the diesel-CME-ethanol blends in various proportions of the components at different temperatures. The stability testing results showed that blends with greater than 5% CME and using ethanol with 100% purity were stable at all observation temperatures. Using the 99.5% pure ethanol, the blends with 2-5% CME content and ethanol content greater than 10% were not stable at temperatures below 25°C. The fuel properties of the blends were found to be within the range of the diesel fuel standard and having values not much in different with commercially available diesel except the flashpoint. Moreover, the addition of ethanol into the blends slightly lowered some of the fuel properties value such as heating value and viscosity. The diesel-CME-ethanol blends at of 90% diesel, 5% CME and...

Atom Indonesia, 2019

To enhance the thermal safety in case of station blackout, a wickless-heat pipe is proposed as an... more To enhance the thermal safety in case of station blackout, a wickless-heat pipe is proposed as an alternative passive cooling system technology to remove decay heat generation in the nuclear spent fuel storage pool. The objectives of this research are to investigate the heat transfer phenomena in vertical straight wicklessheat pipe using Graphene nanofluid working fluid and to study the effect of Graphene nanofluid on the vertical straight wickless-heat pipe thermal performance. The investigation was conducted in 6 meters height and 0.1016 m inside diameter of vertical straight wickless-heat pipe. In this research, the Graphene nanofluid with 1 % of weight concentration was used as working fluid. The effect of working fluid filling ratio, evaporator heat load, and coolant volumetric flow rate on the water jacket were studied. The results showed that the heat transfer phenomena, which were indicated by an overshoot, zigzag, and stable state, were observed. Based on thermal resistance obtained, it was shown that the vertical straight wickless-heat pipe charged with the Graphene nanofluid has a lower thermal resistance compared to one with demineralized water. The thermal resistance of vertical straight wickless-heat pipe using Graphene nanofluid and demineralized water were 0.015 °C/W and 0.016 °C/W, respectively. While the best thermal performance was achieved at a filing ratio of 80 %, higher heat load, and higher coolant volumetric flow rate. It can be concluded that Graphene nanofluid could enhance the thermal performance of vertical straight wickless-heat pipe.

Journal of Physics: Conference Series, 2019

When station blackout occurs on high temperature gas-cooled reactor, the decay heat will be absor... more When station blackout occurs on high temperature gas-cooled reactor, the decay heat will be absorbed by a residual heat dissipation system (known as cooling tank) which connected to the reactor cavity cooling system. The U-shaped heat pipe as passive cooling system is proposed as new feature of technology to absorb the decay heat in the high temperature gas-cooled reactor cooling tank, and to keep the water remains in its operating temperature and level. This research objective is to know thermal resistance of U-shaped heat pipe scale model based on variation of heat load and coolant velocity. The influence of water temperature in the circulating thermostatic bath as heat load on evaporator section and air velocity which flowed into the horizontal condenser fin were investigated experimentally. The heat loads were varied at water temperature of 45, 50, and 60°C. The air velocities were varied at 0.45, 0.83, and 1.06 m/s. The experiment result showed the lowest thermal resistance of 0.000027±0.0000000593 °C/W when U-shaped heat pipe was operated at hot water temperature of 60°C and air velocity of 1.06 m/s. The investigation result can be used as a model and initial knowledge to design large scale of U-shaped heat pipe as a passive cooling system in cooling tanks connected to high temperature gas-cooled reactor cavity cooling system. This result is also useful regarding to the thermal management of passive cooling process in cooling tank and it can improve the nuclear safety and be able to overcome the thermal problems caused by station blackout in high temperature gas-cooled reactor.

ASEAN Journal of Chemical Engineering, 2015

The stability and emission characteristics of diesel-ethanol-coconut methyl ester (CME) blends we... more The stability and emission characteristics of diesel-ethanol-coconut methyl ester (CME) blends were studied to determine the most suitable fuel blends to be applied in diesel engines. This is done in order to assess the potential of the blends as a substitute for commercially available diesel fuel used in diesel engine. The stability results of the blends using 100% and 99.5% ethanol purity showed that the fuel blends containing ethanol up to 10% and CME of 5% and greater exhibited high mutual solubility at any temperature range and were resistant to microbial growths after 3 months storage. Engine operations at low speed especially at idle-no load and using a bigger size engine lead to a minimum ignition delay and result in lower fuel consumption rate. The emission test results with the new- blended fuels showed a reduction in CO2 and increasing percentage by volume of CO2 compared to commercially available diesel. The blends could deliver an efficient combustion and could run effi...

PERHITUNGAN WAKTU HISAP POMPA VAKUM UNTUK START UP PADA KONDISI IDEAL PADA AKSELERATOR ELEKTRON E... more PERHITUNGAN WAKTU HISAP POMPA VAKUM UNTUK START UP PADA KONDISI IDEAL PADA AKSELERATOR ELEKTRON ENERGI TINGGI PRFN. Makalah ini bertujuan untuk melakukan desain awal sistem vakum pada akselerator elektron energi tinggi PRFN, dengan melakukan perhitungan waktu hisap pompa vakum untuk start up pada kondisi ideal, sehingga dapat mendukung operasi pada sistem AEET. Hasil pemvakuman pada akselerator elektron ini berfungsi untuk memudahkan elektron yang dihasilkan dari sumber elektron menuju produk yang akan diiradiasi. Desain sistem vakum akselerator elektron pada penelitian ini menggunakan dua buah pompa, yaitu pompa rotari dan pompa turbomolekuler. Hasil perhitungan menunjukan bahwa pompa rotari memerlukan waktu 15 menit 32 detik dan pompa turbomolekuler memerlukan waktu 22 detik untuk start up pemvakuman. Sehingga waktu hisap keseluruhan yang dibutuhkan untuk menghampakan ruang akselerator elektron adalah 15 menit 54 detik. Desain awal sistem vakum akselerator elektron yang telah dib...

Information on radiation exposures rate and potential of radiation exposures from radiation sourc... more Information on radiation exposures rate and potential of radiation exposures from radiation source in radiation area are important to deliver, so that the potential of radiation hazards that may arise can be controlled. This study was performed to give information about radiation exposures rate inside and outside IGMP main building before and after Cobalt-60 (Co-60) installed inside irradiation room, also radiation exposure potential from Co-60. Measurements were undertaken using survey meter at 51 points inside and 12 points surround the IGMP main building. The results showed that all the radiation exposures rate measurements were below 0.2 μSv/hour. From the results obtained, we can say that IGMP is safe for humans when operating.

PENGKAJIAN TEKNOLOGI PEMBUATAN DETEKTOR PLASTIK SINTILASI. Telah dilakukan kegiatan pengkajian te... more PENGKAJIAN TEKNOLOGI PEMBUATAN DETEKTOR PLASTIK SINTILASI. Telah dilakukan kegiatan pengkajian tentang detektor plastik sintilasi dalam rangka untuk persiapan percobaan laboratorium. Detektor plastik sintilasi merupakan bagian komponen dari portal monitor radiasi (PMR) yang berfungsi untuk mendeteksi adanya sinar gamma. Bahan dasar untuk membuat detektor plastik adalah polimer yang memiliki cincin aromatik yang berfluoresensi dan transparan terhadap panjang gelombang. Polimer atau monomer yang banyak digunakan dalam industri adalah polystyrene (PS) dan polyvinyltoluene (PVT). PVT tidak banyak tersedia di pasaran sedangkan PS banyak tersedia dan harganya relatif murah. Selain bahan dasar, diperlukan juga bahan aditif yaitu aditif primer (PPO atau p-terphenyl) dan aditif sekunder (POPOP). Aditif primer dan sekunder berfungsi mengubah emisi foton energi tinggi menjadi kerlipan sintilasi pada panjang gelombang sinar tampak 400 ~ 500 nm. Pencampuran bahan dasar dan aditif dilakukan pada ...

Journal of Physics: Conference Series, Feb 1, 2018

An analysis of radiation penetration through the U-shaped joints of cast concrete shielding in BA... more An analysis of radiation penetration through the U-shaped joints of cast concrete shielding in BATAN's multipurpose gamma irradiator has been carried out. The analysis has been performed by calculating the radiation penetration through the U-shaped joints of the concrete shielding using MCNP computer code. The U-shaped joints were a new design in massive concrete construction in Indonesia and, in its actual application, it is joined by a bonding agent. In the MCNP simulation model, eight detectors were located close to the observed irradiation room walls of the concrete shielding. The simulation results indicated that the radiation levels outside the concrete shielding was less than the permissible limit of 2.5 μSv/h so that the workers could safely access electrical room, control room, water treatment facility and outside irradiation room. The radiation penetration decreased as the density of material increased.

A NOVEL DESIGN OF 17.5 KV HV FEEDTHROUGH FOR ARJUNA 2.0. A novel design of the 17.5 kV feedthroug... more A NOVEL DESIGN OF 17.5 KV HV FEEDTHROUGH FOR ARJUNA 2.0. A novel design of the 17.5 kV feedthrough for Arjuna 2.0 Cockcroft Walton generator has been proposed. It is used for connecting the output of RF transformer oscillator (in the outside of horizontal vessel) with the input of voltage multiplier (inside of horizontal vessel) of the Cockcroft Walton generator. It was equipped by covers on left and right side. The designed feedthrough was simple, compact, easy to manufacture, high performance to prevent flashover and also it was applied to Arjuna 2.0 Cockcroft Walton. It was made from teflon (PTFE) and solid copper, which have high dielectric strength, capable of withstanding press loads, and easy to manufacture. The shortest distance between grounding with conductor radially was 43.25 mm, and 253.5 mm for feedthrough surface. The design was verified by Finite Element Method software and continued with performance testing. According to simulation, the stress of voltage is high abo...

E3S Web of Conferences

Indonesia is rich in diversity of agroindustrial products. Yet the tropical climate causes agroin... more Indonesia is rich in diversity of agroindustrial products. Yet the tropical climate causes agroindustrial products being easily damaged. Techniques for food preservation have been widely known such as drying, cooling or freezing, canning, chemical use and others. To complement these techniques, a promising unconservative technique using ionizing radiation can be safely used to preserve food, without leaving residual radiation or hazardous chemical residues. Unfortunately in Indonesia, the irradiation technique was still not common since few industries have used this technique. Compared to the neighbouring countries, only Indonesia as a big country had no interest in developing irradiator technology. To introduce this technique to the public, especially investors, BATAN in 2017 built a pilot project named as Iradiator Gamma Merah Putih (IGMP). It was designed with maximum activity up to 2 MCi using Cobalt-60 as radioactive sources and can serve from low to high dose. By the time, the...

E3S web of conferences, 2024

The working principle of the combined cycle in the combined cycle power plant (CCPP) is to utiliz... more The working principle of the combined cycle in the combined cycle power plant (CCPP) is to utilize a certain amount of waste heat in the gas turbine, which reaches temperatures of 1650°C, to generate steam in the steam turbine. Due to the high temperature of the exhaust gas in the gas turbine, a device is needed to recover this waste heat, known as a Heat Recovery Steam Generator (HRSG). Compared to conventional HRSG, a once-through heat recovery steam generator (OTHRSG) offers the advantages of faster design time (25% faster than conventional) and lower design costs because it does not require a drum which contributes to an increase in thermal efficiency. This study aims to model and simulate the CCPP system with an OTHRSG to achieve maximum thermal efficiency by using biogas from the degradation of organic waste as the input fuel for CCPP using Cycle Tempo software. The thermal efficiency of the CCPP system was achieved at 57% by applying turbine inlet temperature (TIT) of 1500°C and compression ratio of 46. These results proved that the CCPP system by using biogas as fuel could increase the thermal efficiency of a single cycle power plant.

XVII MEXICAN SYMPOSIUM ON MEDICAL PHYSICS

Nucleation and Atmospheric Aerosols, 2019

h i g h l i g h t s A 3D coupled thermo-hydrogeological numerical model of an ATES system is pres... more h i g h l i g h t s A 3D coupled thermo-hydrogeological numerical model of an ATES system is presented. Importance of a few parameters involved in the study is determined. Thermal energy discharge by the ATES system for two seasons is estimated. A strategy and a safe well spacing are proposed to avoid thermal interference. The proposed model is applied to simulate a real life ATES field study.

Atom Indonesia, Apr 16, 2019

In order to anticipate station blackout, the use of safety system based on passive features is hi... more In order to anticipate station blackout, the use of safety system based on passive features is highly considered in advanced nuclear power plant designs, especially after the Fukushima Dai-ichi nuclear power station accident. An example is the application of natural circulation in the emergency cooling system. To study the reliability of such an application, a research project on natural circulation was carried out. This paper describes the investigation results on the natural circulation phenomena obtained using a large rectangular experimental loop named FASSIP-01. The experiments were conducted at two different heat source powers. The experimental results are analysed using existing correlation and numerical model simulation. The RELAP5 system code is applied to model the natural circulation. FLUENT computational fluid dynamic code is used to visualize the flow distribution. The experimental results show the establishment of stable natural circulation in all heat power input with the mass flow rate of about 0.0012 kg/s. Calculation using the existing correlation shows that the experimental Reynold numbers are lower than predicted by the correlation. The computational fluid dynamics-based tool could show the three dimensional distribution of the temperature, while the model of RELAP5 predict well the dynamic of the singlephase natural circulation established in the experimental loop. It is concluded that the stable natural circulation have been established in the large rectangular loop and the model of the RELAP5 could simulate the observed natural circulation phenomenon reasonably well.

Spektra: jurnal fisika dan aplikasinya, Dec 30, 2022

Experiments on making a plastic scintillator with polystyrene as a base material mixed with fluor... more Experiments on making a plastic scintillator with polystyrene as a base material mixed with fluorescent compounds (primary and secondary dopants) have been performed. Primary dopants (PTP) used to produce emission at wavelengths of visible light and secondary dopants (POPOP) to shift the visible wavelengths to wavelengths that could be detected by Photomultiplier Tube (PMT)) were carried out. Experiments were performed on the melting points condition of these materials, which had previously been subjected to a thermo-mechanical analysis using a Thermogravimetric Analysis-Differential Scanning Calorimetry (TGA-DSC) machine, where the melting point was in the range of 200-240°C. Furthermore, the fabrication was carried out using the extrusion technique, where polystyrene pellets mixed with PTP (1.5% by weight) and POPOP (0.05% by weight) were fed into an extrusion machine which has four hot areas to obtain a thin plate plastic scintillator. The plates were then analyzed with a UV-Vis Spectrophotometer to determine the absorption spectrum and Fluorescence Spectrophotometer to determine the emission spectrum. From the results of the analysis, it was found that the samples that went through scintillation pellets and without the addition of antioxidants had absorption spectrum data of 330 nm and emission spectrum of 421 nm. These values are in

Atom Indonesia, Dec 12, 2019

To enhance the thermal safety in case of station blackout, a wickless-heat pipe is proposed as an... more To enhance the thermal safety in case of station blackout, a wickless-heat pipe is proposed as an alternative passive cooling system technology to remove decay heat generation in the nuclear spent fuel storage pool. The objectives of this research are to investigate the heat transfer phenomena in vertical straight wicklessheat pipe using Graphene nanofluid working fluid and to study the effect of Graphene nanofluid on the vertical straight wickless-heat pipe thermal performance. The investigation was conducted in 6 meters height and 0.1016 m inside diameter of vertical straight wickless-heat pipe. In this research, the Graphene nanofluid with 1 % of weight concentration was used as working fluid. The effect of working fluid filling ratio, evaporator heat load, and coolant volumetric flow rate on the water jacket were studied. The results showed that the heat transfer phenomena, which were indicated by an overshoot, zigzag, and stable state, were observed. Based on thermal resistance obtained, it was shown that the vertical straight wickless-heat pipe charged with the Graphene nanofluid has a lower thermal resistance compared to one with demineralized water. The thermal resistance of vertical straight wickless-heat pipe using Graphene nanofluid and demineralized water were 0.015 °C/W and 0.016 °C/W, respectively. While the best thermal performance was achieved at a filing ratio of 80 %, higher heat load, and higher coolant volumetric flow rate. It can be concluded that Graphene nanofluid could enhance the thermal performance of vertical straight wickless-heat pipe.

Spektra: Jurnal Fisika dan Aplikasinya

Experiments on making a plastic scintillator with polystyrene as a base material mixed with fluor... more Experiments on making a plastic scintillator with polystyrene as a base material mixed with fluorescent compounds (primary and secondary dopants) have been performed. Primary dopants (PTP) used to produce emission at wavelengths of visible light and secondary dopants (POPOP) to shift the visible wavelengths to wavelengths that could be detected by Photomultiplier Tube (PMT) ) were carried out. Experiments were performed on the melting points condition of these materials, which had previously been subjected to a thermo-mechanical analysis using a Thermogravimetric Analysis-Differential Scanning Calorimetry (TGA-DSC) machine, where the melting point was in the range of 200-240°C. Furthermore, the fabrication was carried out using the extrusion technique, where polystyrene pellets mixed with PTP (1.5% by weight) and POPOP (0.05% by weight) were fed into an extrusion machine which has four hot areas to obtain a thin plate plastic scintillator. The plates were then analyzed with a UV-Vis...

Coconut methyl ester (CME) or coconut oil biodiesel was chosen as the emulsifier for the diesel-e... more Coconut methyl ester (CME) or coconut oil biodiesel was chosen as the emulsifier for the diesel-ethanol blends. This study involved the stability testing and determination of physical and emission properties of the diesel-CME-ethanol blends in various proportions of the components at different temperatures. The stability testing results showed that blends with greater than 5% CME and using ethanol with 100% purity were stable at all observation temperatures. Using the 99.5% pure ethanol, the blends with 2-5% CME content and ethanol content greater than 10% were not stable at temperatures below 25°C. The fuel properties of the blends were found to be within the range of the diesel fuel standard and having values not much in different with commercially available diesel except the flashpoint. Moreover, the addition of ethanol into the blends slightly lowered some of the fuel properties value such as heating value and viscosity. The diesel-CME-ethanol blends at of 90% diesel, 5% CME and...

Atom Indonesia, 2019

To enhance the thermal safety in case of station blackout, a wickless-heat pipe is proposed as an... more To enhance the thermal safety in case of station blackout, a wickless-heat pipe is proposed as an alternative passive cooling system technology to remove decay heat generation in the nuclear spent fuel storage pool. The objectives of this research are to investigate the heat transfer phenomena in vertical straight wicklessheat pipe using Graphene nanofluid working fluid and to study the effect of Graphene nanofluid on the vertical straight wickless-heat pipe thermal performance. The investigation was conducted in 6 meters height and 0.1016 m inside diameter of vertical straight wickless-heat pipe. In this research, the Graphene nanofluid with 1 % of weight concentration was used as working fluid. The effect of working fluid filling ratio, evaporator heat load, and coolant volumetric flow rate on the water jacket were studied. The results showed that the heat transfer phenomena, which were indicated by an overshoot, zigzag, and stable state, were observed. Based on thermal resistance obtained, it was shown that the vertical straight wickless-heat pipe charged with the Graphene nanofluid has a lower thermal resistance compared to one with demineralized water. The thermal resistance of vertical straight wickless-heat pipe using Graphene nanofluid and demineralized water were 0.015 °C/W and 0.016 °C/W, respectively. While the best thermal performance was achieved at a filing ratio of 80 %, higher heat load, and higher coolant volumetric flow rate. It can be concluded that Graphene nanofluid could enhance the thermal performance of vertical straight wickless-heat pipe.

Journal of Physics: Conference Series, 2019

When station blackout occurs on high temperature gas-cooled reactor, the decay heat will be absor... more When station blackout occurs on high temperature gas-cooled reactor, the decay heat will be absorbed by a residual heat dissipation system (known as cooling tank) which connected to the reactor cavity cooling system. The U-shaped heat pipe as passive cooling system is proposed as new feature of technology to absorb the decay heat in the high temperature gas-cooled reactor cooling tank, and to keep the water remains in its operating temperature and level. This research objective is to know thermal resistance of U-shaped heat pipe scale model based on variation of heat load and coolant velocity. The influence of water temperature in the circulating thermostatic bath as heat load on evaporator section and air velocity which flowed into the horizontal condenser fin were investigated experimentally. The heat loads were varied at water temperature of 45, 50, and 60°C. The air velocities were varied at 0.45, 0.83, and 1.06 m/s. The experiment result showed the lowest thermal resistance of 0.000027±0.0000000593 °C/W when U-shaped heat pipe was operated at hot water temperature of 60°C and air velocity of 1.06 m/s. The investigation result can be used as a model and initial knowledge to design large scale of U-shaped heat pipe as a passive cooling system in cooling tanks connected to high temperature gas-cooled reactor cavity cooling system. This result is also useful regarding to the thermal management of passive cooling process in cooling tank and it can improve the nuclear safety and be able to overcome the thermal problems caused by station blackout in high temperature gas-cooled reactor.

ASEAN Journal of Chemical Engineering, 2015

The stability and emission characteristics of diesel-ethanol-coconut methyl ester (CME) blends we... more The stability and emission characteristics of diesel-ethanol-coconut methyl ester (CME) blends were studied to determine the most suitable fuel blends to be applied in diesel engines. This is done in order to assess the potential of the blends as a substitute for commercially available diesel fuel used in diesel engine. The stability results of the blends using 100% and 99.5% ethanol purity showed that the fuel blends containing ethanol up to 10% and CME of 5% and greater exhibited high mutual solubility at any temperature range and were resistant to microbial growths after 3 months storage. Engine operations at low speed especially at idle-no load and using a bigger size engine lead to a minimum ignition delay and result in lower fuel consumption rate. The emission test results with the new- blended fuels showed a reduction in CO2 and increasing percentage by volume of CO2 compared to commercially available diesel. The blends could deliver an efficient combustion and could run effi...

PERHITUNGAN WAKTU HISAP POMPA VAKUM UNTUK START UP PADA KONDISI IDEAL PADA AKSELERATOR ELEKTRON E... more PERHITUNGAN WAKTU HISAP POMPA VAKUM UNTUK START UP PADA KONDISI IDEAL PADA AKSELERATOR ELEKTRON ENERGI TINGGI PRFN. Makalah ini bertujuan untuk melakukan desain awal sistem vakum pada akselerator elektron energi tinggi PRFN, dengan melakukan perhitungan waktu hisap pompa vakum untuk start up pada kondisi ideal, sehingga dapat mendukung operasi pada sistem AEET. Hasil pemvakuman pada akselerator elektron ini berfungsi untuk memudahkan elektron yang dihasilkan dari sumber elektron menuju produk yang akan diiradiasi. Desain sistem vakum akselerator elektron pada penelitian ini menggunakan dua buah pompa, yaitu pompa rotari dan pompa turbomolekuler. Hasil perhitungan menunjukan bahwa pompa rotari memerlukan waktu 15 menit 32 detik dan pompa turbomolekuler memerlukan waktu 22 detik untuk start up pemvakuman. Sehingga waktu hisap keseluruhan yang dibutuhkan untuk menghampakan ruang akselerator elektron adalah 15 menit 54 detik. Desain awal sistem vakum akselerator elektron yang telah dib...

Information on radiation exposures rate and potential of radiation exposures from radiation sourc... more Information on radiation exposures rate and potential of radiation exposures from radiation source in radiation area are important to deliver, so that the potential of radiation hazards that may arise can be controlled. This study was performed to give information about radiation exposures rate inside and outside IGMP main building before and after Cobalt-60 (Co-60) installed inside irradiation room, also radiation exposure potential from Co-60. Measurements were undertaken using survey meter at 51 points inside and 12 points surround the IGMP main building. The results showed that all the radiation exposures rate measurements were below 0.2 μSv/hour. From the results obtained, we can say that IGMP is safe for humans when operating.

PENGKAJIAN TEKNOLOGI PEMBUATAN DETEKTOR PLASTIK SINTILASI. Telah dilakukan kegiatan pengkajian te... more PENGKAJIAN TEKNOLOGI PEMBUATAN DETEKTOR PLASTIK SINTILASI. Telah dilakukan kegiatan pengkajian tentang detektor plastik sintilasi dalam rangka untuk persiapan percobaan laboratorium. Detektor plastik sintilasi merupakan bagian komponen dari portal monitor radiasi (PMR) yang berfungsi untuk mendeteksi adanya sinar gamma. Bahan dasar untuk membuat detektor plastik adalah polimer yang memiliki cincin aromatik yang berfluoresensi dan transparan terhadap panjang gelombang. Polimer atau monomer yang banyak digunakan dalam industri adalah polystyrene (PS) dan polyvinyltoluene (PVT). PVT tidak banyak tersedia di pasaran sedangkan PS banyak tersedia dan harganya relatif murah. Selain bahan dasar, diperlukan juga bahan aditif yaitu aditif primer (PPO atau p-terphenyl) dan aditif sekunder (POPOP). Aditif primer dan sekunder berfungsi mengubah emisi foton energi tinggi menjadi kerlipan sintilasi pada panjang gelombang sinar tampak 400 ~ 500 nm. Pencampuran bahan dasar dan aditif dilakukan pada ...

Journal of Physics: Conference Series, Feb 1, 2018

An analysis of radiation penetration through the U-shaped joints of cast concrete shielding in BA... more An analysis of radiation penetration through the U-shaped joints of cast concrete shielding in BATAN's multipurpose gamma irradiator has been carried out. The analysis has been performed by calculating the radiation penetration through the U-shaped joints of the concrete shielding using MCNP computer code. The U-shaped joints were a new design in massive concrete construction in Indonesia and, in its actual application, it is joined by a bonding agent. In the MCNP simulation model, eight detectors were located close to the observed irradiation room walls of the concrete shielding. The simulation results indicated that the radiation levels outside the concrete shielding was less than the permissible limit of 2.5 μSv/h so that the workers could safely access electrical room, control room, water treatment facility and outside irradiation room. The radiation penetration decreased as the density of material increased.

A NOVEL DESIGN OF 17.5 KV HV FEEDTHROUGH FOR ARJUNA 2.0. A novel design of the 17.5 kV feedthroug... more A NOVEL DESIGN OF 17.5 KV HV FEEDTHROUGH FOR ARJUNA 2.0. A novel design of the 17.5 kV feedthrough for Arjuna 2.0 Cockcroft Walton generator has been proposed. It is used for connecting the output of RF transformer oscillator (in the outside of horizontal vessel) with the input of voltage multiplier (inside of horizontal vessel) of the Cockcroft Walton generator. It was equipped by covers on left and right side. The designed feedthrough was simple, compact, easy to manufacture, high performance to prevent flashover and also it was applied to Arjuna 2.0 Cockcroft Walton. It was made from teflon (PTFE) and solid copper, which have high dielectric strength, capable of withstanding press loads, and easy to manufacture. The shortest distance between grounding with conductor radially was 43.25 mm, and 253.5 mm for feedthrough surface. The design was verified by Finite Element Method software and continued with performance testing. According to simulation, the stress of voltage is high abo...

E3S Web of Conferences

Indonesia is rich in diversity of agroindustrial products. Yet the tropical climate causes agroin... more Indonesia is rich in diversity of agroindustrial products. Yet the tropical climate causes agroindustrial products being easily damaged. Techniques for food preservation have been widely known such as drying, cooling or freezing, canning, chemical use and others. To complement these techniques, a promising unconservative technique using ionizing radiation can be safely used to preserve food, without leaving residual radiation or hazardous chemical residues. Unfortunately in Indonesia, the irradiation technique was still not common since few industries have used this technique. Compared to the neighbouring countries, only Indonesia as a big country had no interest in developing irradiator technology. To introduce this technique to the public, especially investors, BATAN in 2017 built a pilot project named as Iradiator Gamma Merah Putih (IGMP). It was designed with maximum activity up to 2 MCi using Cobalt-60 as radioactive sources and can serve from low to high dose. By the time, the...